Since more and more mobile phones provide web browsing capability, more and more people are using mobile phones to access the web. However, the small display screen and the limited input capabilities of mobile devices often do not give the user a satisfactory browsing experience. Although many attempts are being made to address this problem, such as through re-authoring or pre-processing by the browser before rendering, fitting a complex webpage designed for the desktop computer into the screen of a mobile device remains a great challenge.
Browsing the web using a mobile device does not often lead to a satisfactory experience, since most existing webpages are designed for access by a desktop or notebook computer which has a large screen. For a mobile device, it is difficult to:
1. fit a webpage to a small screen, typically less than 400 pixels in any dimension;
2. navigate the webpage using the scrolling buttons and a small keypad.
Although current problems of processing power and communication bandwidth of mobile devices will be solved in due course, the small screens and limited input facilities are features that will remain as a challenge. Several approaches have been proposed to process ordinary webpages for mobile web browsing: one solution is “small screen rendering” (SSR) or “narrow layout”, which reorganizes the webpage to a long and thin column in order to fit the width of the devices [8]. Another approach uses “thumbnail” or “overview plus detail” (OPD), displays. When implementing the “thumbnail” or “overview plus detail” (OPD) display, the whole webpage appears on the screen as a thumbnail image and allows zooming into a particular section. The Mobile Web Initiative of the World Wide Web Consortium (W3C) offers design tips, called “best practices” (hereafter referred to as the “W3C Best Practices Recommendation”), intended to make either the SSR or the OPD approach work better, provided the webpage designer has possible rendering on mobile devices in mind.
Both the SSR and OPD approaches have similar disadvantages. Both transmit much more content to the mobile device than the user actually wants. Therefore, if the user is interested in only a small section of a webpage, which is often the case, it may take too much time and navigation effort to find that section. A good browsing experience occurs when users can see the requested content soon after the page has been loaded, without excessive scrolling or clicking through multiple links.
A further disadvantage is inherent in the more limited scope of information provided on a mobile device display. When a webpage is created, the webpage creator attempts to optimize display “real estate” to provide a combination of necessary information and ancillary information on the screen. To the extent that whatever information desired by the user is easily accessed by the user, the ancillary information is ignored (or sometimes blocked). The SSR and OPD renderings may or may not provide the information desired by the user either because the webpage creator cannot anticipate what the information desired by the viewer is or because the desired information varies from viewer to viewer. In addition, commercial considerations may mitigate against the webpage creator providing concise information for possible displaying on a small screen.